Turning off the donkey in flight. Yes or No?

[Wee Weasley Welshman]

I am following on a discussion thread in Wannabes entitled 'Crashes - they happen'.

The thread is a little large and off topic now so I've started it here. Go read it.

Personally I've done plenty of engine off landings but in motor gliders whichmust be safe becasue it was done with the Air Training Corps and that it overseen by Central Flying School RAF. I've been in Group A aircraft when its been done but I don't condone it and was not the captain. I absolutely hate the people who liek to take out the keys etc and throw them in the back/dangle them out of the window.

What do you think/do?

WWW

[BEagle]

It's quite normal to shut down the single engine of a self-launching motor glider. However, in a 'Group A'(old term) aeroplane I personally think that it is crass stupidity to do so. And anyone who dangles the keys out of the window should be dangled out of the window themselves!
I couldn't find any reference to deliberate engine shut-downs in single-engined aeroplanes in the AIC concerning guidance to training captains conducting engine failure training - either the CAA cannot believe that any one would deliberately do so, or the topic is covered elsewhere?

[Charlie Foxtrot India]

When in doubt of the wisdom of these things, think to yourself "If the worst happens, will the insurance company pay up?" If the answer is no, don't do it.

I think insurance companies would crack up laughing at this one. Including the life insurance companies, I think it would probably be classified as suicide.

------------------

[DB6]

I personally would like to try it at least once, but with only myself in the plane and not for a couple of thousand more hours yet. However although I'm not the sort of chap to thump people, I probably would if somebody did it to me. While I'm sure it has some benefit as a training exercise (which is why I'd like to try it) I can't help but feel the minuses more than outweigh the pluses.
Cheers DB6

[Vigilant Driver]

No you don't want to switch off the donkey, particularly in winter as the heater stops working!!

Like you WWW I have done lots of eng off in the motor glider. Thats okay as we typically lose 200FPM. In the Cherry Tree its more like 1000FPM. Much less time to restart the eng in case of b*lls ups!

I was certainly never taught to switch the engine off in the air during my AFI.

Did switch the right engine off in the Seneca during my twin training. We almost maintained straight and level flight!

[climbs like a dog]

I have been shown the prop-stopped handling of a piston single. Thought it an experience but wouldn't teach it to my PPL students.
Definitely agree with the sentiments about insurance.

Don't think it's safe to even do it in favourable circumstances, ie at a reasonable height in the overhead of a suitable airfield on a 5kt-straight-down-the-runway sort of day, because you're leaving a big hostage to fortune (will it or won't it start) and you can bet that if your luck's out in the engine dept, it's bound to be out in other ways too.

------------------
Get there eventually

[rolling circle]

I've let this one run a bit without comment because I could not believe the original question was serious.

Having discussed it with a colleague at SRG, the party line is that, should such stupidity come to the ears of the Authority, they would seriously consider a prosecution on the grounds of reckless endangerment. The idiot's licence would not last long in any event.

[Checkboard]

It depends on your definitions: "turning off the engine" can mean simply pulling the mixture for a practice engine failure.

That is a required part of light aircraft training! Glide approaches from base - as the Practice Forced Landing is rarely completed to landing in a paddock, I would have done this with every student.

Turning off the mags (switching off the keys) is a little rarer - removing the keys is stupidity, as it serves no training purpose.

Stopping the prop? I was introduced to this in my aerobatic rating, and it happens as a matter of course in a power off spin in a Robin (at least the one I fly) so it has a positive training value to demonstrate restarts to students who intend to fly aerobatics - both with the starter motor and using a dive start technique.

I wouldn't stop the prop for a glide approach and landing, though, as I cannot see any training benefit over a glide approach with a windmilling prop - and a much larger risk increase, as in the "remove the key" case.

[skyvan]

I have to say, from a realism point of view, shutting down the engine cannot be more true to life, but what will the commision of enquiry think of it? Bloody stupid idea!
On my second PPL renewal, the examiner did just that to me (pulled the mixture) inspite of my warning him beforehand that if the engine did die, I'd treat it as an emergency. I terminated the test there and then, and returned to the field, where the examiner was treated to my grumpiest style of disagreement. (before my CRM course! :) )
I tested the next day with a proper instructor, and passed!
Now that I am an instructor, in the pre-test briefing, I make sure that the candidate is fully aware that if the engine dies, we have a full emergency. I don't even simulate the engine failure after take-off at our base, because of too many houses nearby, I prefer to do it on the Go-around from either the forced landing or the precautionary.
As an aside, the local parachute club had a couple of jokers who liked to take the keys with them as the dispatched, until a rather large Irish mate of mine was flying. On the completion of the successful landing, the skydiver spent a weekend in hospital for wounds recieved during the "de-briefing".
In brief, don't do it, and don't fly with those who do!

[Wee Weasley Welshman]

What about doing it on the AFI course for us instructors? I think there may be some benefit to doing it as it is perfectly possible for us to encounter the engine stopping during stalling or spinning. Its happened to me twice and although I've experienced it going very very quiet many times in the Vigilant MG it could easily instill panic in a new instructor. If we practice spin recovery then it seems to me the an actual engine stop carries equal risk and is equally as likely to be encountered and cause panic.

Just a thought.

WWW

ps removing the keys ought to be a criminal offence.

[Wee Weasley Welshman]

This thread is also running in Tech Log forum.


WWW

[BEagle]

.......and start a small fire in the cabin so the student instructor can practise dealing with those as well??
Spoke to a very experienced instructor who teaches SLMG and PPL yesterday. The basic difference is that the half-airbrake approach in an SLMG is a totally different technique to the glide approach or FLWOP in a Spamcan. My Flying Order Book specifically prohibits using the ignition or mixture controls to simulate an engine failure in a single-engined aircraft. I would immediately pass the details of any pilot who disobeyed these orders to the CAA's enforcement branch and urge that the miscreant be prosecuted with the maximum severity. After we'd finished kicking the living !!!!! out of him!!

[Meeb]

This is interesting, with some very emotive discussion! If anyone cares to consult the CAA syllabus you will find a section under emergencies titled 'air starts', this is the technique of using altitude and attitude to re-start a failed engine with a stationary prop. All quite legit, so the SRG are lacking a bit on this one BEagle!

When I was a 509 instructor the HoT (he was also Standards) took me to one side and asked me how I was teaching this, I gulped and said I was'nt, he smiled in his usual wry manner and said 'ok lets try it'! I was, I admit, a wee bit apprehensive, but I was all for trying something new. We went up to above 5 grand and stopped the engine and the prop and glided for half a minute or so, exploring the characteristics then re-started it with no drama. We did both key start and air start. No throwing the keys in the back seat or dangling out the window, that is plain stupid and silly.

I was converted after this, and it is a valuable lesson to teach that an engine can be restarted even when the prop has stopped, and it shows how the aircraft can still be handled normally if the prop is stationary, and in this we prove the glide after a catistrophic engine failure.

There we have it, all legal and proper!

[Tinstaafl]

It seems my original post that WWW refers has kicked of a great professional debate. BEagle already knows my views about the subject however...

I think a prop stopped exercise is a valuable training situation. I don't believe that removing the keys, tossing 'em in the back or hanging them out the window is responsible or ethical.

What I DO maintain is that a properly structured exercise is a beneficial task for the student and poses little more risk (if any) than say, asymmetric rejected take-offs. To differentiate from gliders or any other non-powered, heavier-than-air type is fallacious. As long as the aircraft is operated within it's glide performance envelope then what's the difference?

I, too, was required to do prop stopped, air & starter motor restarts for both my initial aerobatics endorsement & later my aero. instructor approval. In both cases the situation was set up over an airstrip, with enough height to use either direction + no TFC. Of course the controls were set for a restart once the engine was stopped.

There is a large change in glide performance between an idling & a stopped engine. It can make a few hundred ft/min difference & that's only a Cessna 150!.

As for the argument about 'what if someone cuts in front?' - then land beside / behind as appropriate. Similarly this is no different to doing a shutdown & feathered approach & landing in a light twin. Once commital height is reached then that's what it means.

My (twin) students were in no doubt about going around or not below decision height if I gave them an asymmetric approach. (Of course I told them that I might countermand their decision if it was a non-feathered situation. But the message was: If the performance doesn't allow it - then don't try it.)

I really can't see the difference.

Doing it at Bankstown (one of the busiest GA aerodromes in the S. hemisphere? No, of course not. Doing at Upper Whoop Whoop airstrip as nearly the sole operator? Different story.

As an aside, just try the bloody shaking & vibration that happens at best glide IAS with a windmilling but stopped engine. It really can be horrendous.


------------------
Don't mess with the red switches.

[BEagle]

We'll have to agree to differ mate!! And I'm convinced by my SLMG mucker that flying a glide approach in a Spamcan and flying a half-airbrake approach in a glider or SLMG are most emphatically not the same thing!! But if you've got hundreds of Oz miles available in all directions, then I guess things are different to over here in Blighty!! Oh-and I flew a T67 a couple of years ago (useless damn thing it was too - desperately poor roll rate for half-decent aeros!!) which invariably went silent (prop stopped) if the student got lost in the vertical. Always started on pressing the tit - but I certainly always stayed within gliding range of a reasonable aerodrome as I'd never be overconfident enough to assume that the little sod wouldn't let me down when I least expected it to!!

[rolling circle]

Far be it from me to prevent anyone from being a total prat if they so wish. Just bear in mind that you are putting your career on the line if SRG find out about it.

IMHO, if you are that stupid, you are no loss to the profession.

[Tinstaafl]

BEagle,

I figured in the other thread we'd have to agree to differ. Doesn't negate discussing the pro's & cons of the topic though.

I too have always stayed within gliding range of an aerodrome for engine stoppages.

I'm interested in what your friend said about it none the less. Feel free to email me if you prefer.

----------
Tinny with the outbourd stopped :-)

[Wee Weasley Welshman]

But what about my point of including the exercise in the FI training course? Must admit I've only ever done one proper windmill air start before (SLMG again) - not sure how efficiently I could try one in my current PA38/28's... might come in useful some day.

WWW

[Bendo]

Doing it at 3000', practicing aeros or spin recoveries, is very different to deliberately killing the donk and trying to glide the bastard in.

As a student my CFI had delusions of Hoover and used shut down the Decathlon at 4000' over the field, do aeros all the way down to 500', land and taxi in to the school. One day he misjudged the winds and couldn't restart the Donk... we all had to go out and push him in from the end of the runway.

Another fella I know was doing a checkout in remote NW Ozmate at night.... the Chief pilot failed the lights on him. He was trying to hold the torch in his mouth etc etc etc when the chief pilot pulled the mixture... and a Cessna 206 doesn't glide real well!

The Chief Pilot was promptly told to get knotted and J. restarted the engine, landing without incident.

As Col Pay says, "Why turn a practice emergency into a real one?"

[Terrain Terrain]

(This is the transfer of a reply to this thread that was posted in 'Tech Log'. CFI: Damn good point about insurance. The practice would have to be in Ops Manual).

What a marvellous topic. I recall this starting a rather heated debate back in my
instructing days. In viewpoint is
(re: pistons)....

TWIN
----
For engine failures, simulate by closing the throttle. Set zero thrust when student completes drill. Never simulate by 'slotting' the mixture. Exception? Yes. I am a firm
believer in experiencing a fully feathered approach. Thus, full engine shutdown is ok if
1,000'+ and ATC is notified (to keep traffic away).

SINGLE
------
Provided a decision height is chosen (the point at which any attempt to restart the
engine is abandoned and the pilot commits himself to a forced landing, I see no problem
in doing so. I had MY instructor take the keys out of the IGN once. I never did that.
You are just asking for trouble. Delib. shutting down of an engine is of benefit to teach the student (1. the aircraft really DOES still fly, 2. how to do an airstart and 3. How much fun a silent barrel roll is). Shut down of an engine during a PFL would kill your ability to have a decision/committal height (thus VERY unwise).

This is just my opinion. Let the debate continue. :)

[Wee Weasley Welshman]

Sorry to press on this buy if we forget about this exercise for students what about for instructors?

In my limited experience I have had the engine stop on me, once in a spin and once in a stall. Surely there is merit in us having experienced the panic inducing silence at least once under controlled conditions.

WWW

[Ozgrade3]

I agree with WWW, as long as the exercise is done in a controlled situation, ie., over a suitable aerodrome, with altitude to spare(and keys still in the ignition), it should be done. I got the experience of an air restart as part of my initial instructor rating. This was done in a C150 Aerobat.

Like hand-swinging a prop to start the engine, it's something I'm glad I've done once under supervision, but I'm also in no rush to do it again.

[climbs like a dog]

I still stand by my point about the basic safety of shutting down the engine of a light single. There is no necessity for it. Twins, I had no qualms about the exercise shutting down an engine during my B rating (during a course at OATS) as this was carried out under a definite set of rules (above 3000, nearby suitable diversion airfield, etc) AND you weren't just going downhill with no power, although I do accept safety levels were (acceptably IMHO) decreased.

I'm sure that insurance companies would class a single with a stopped engine as an emergency situation and not as a normal flight manouvre - even if it were stopped deliberately.

What would the exercise demonstrate? That an aircraft flies well with the prop stopped and the difference in drag between a stopped prop and an idling, no power, prop. All very well but why are we doing it? Because it may impact on actual glide performance on the day of a real failure as opposed to what they are used to from their PFL training? Surely, this is down to ensuring that good PFL techniques are taught and maintained post-training. A better way of simulating a degradation of glide performance would be to start the glide with 10 degrees of flap.

I've bemoaned some aspects of JAR as I don't think they've been properly thought through. Taking a narrow PPL / PPL training view the new PPL requirement to fly with an instructor every two years is a good one and should raise the overall standard of PFL's because, whether the risky shutdown and restart procedure is shown or not, if they can't execute a safe forced landing the whole exercise is a waste of time.



------------------
Get there eventually

[Wee Weasley Welshman]

You'd be showing (not the same as knowing) instructors-to-be that the engine stopping need not be an instant MAYDAY, panic, look for a field situation. Hell - we have to be able to get out of spins and simulate engine fires. I've experienced neither but have had the engine stop more than once only for a re-start to be completed.

WWW

[Capt Homesick]

I can go along- just- with the idea of stopping the engine during the AFI course. I would prefer to do that at altitude, preferably wearing parachutes. I've had too many experiences of a warm Lycoming refusing to start, to want to try that in the air. Embarrassment I can cope with, but I don't want the AAIB to ever know mmy name!
And with all due respect to CFI, if anyone ever gives me an EFATO in a single with the mixture control instead of the throttle, the test is over, I'm treating it as a real emergency- and when I get on the ground, I'm phoning the CAA. Oh, and I won't be paying for the flight, either!

[Checkboard]

What is the difference between simulating an engine failure by pulling the mixture or the throttle?!

I always used the mixture - a bit less stress on the carby and induction bits (as the throttle buttlerfly remains open), and the chances of the mixture getting stuck in the off position are the same as the throttle getting stuck.

(In fact one of my company's students had a stuck throttle on first area solo, and performed a textbook PFL into a clear paddock with no damage to aircraft or student.)

[Wee Weasley Welshman]

Simulated EFATO by means of Mixture ICO????!!!!!????

Are you joking Sir?

WWW

[The Jester]

Having had 2 engines spit the dummy on me in my time as a QFI I see no reason to deliberately risk putting yourself in that situation! Doing it in a twin at medium level is one thing, but a single?? NO.

[Meeb]

WWW, in Australia they use the mixture control to simulate an engine failure, but only on twins, it is the throttle on single engine PFL's. I found it strange at first, but after getting used to it it makes sense. Personaly I prefer to use the mixture, but our CAA will not allow it of course, and they issued a lengthy AIC to back up their position.

[Corporate Yank]

If you're flying engines that have crankshaft counterweights, (PA31P/LYC-TIGO-541A) for example, the crank counterweights, bushings, and pins take a terrible mechanical beating that can set you up for a catastrophic mechanical failure by rapidly retarding/opening the throttle. Mixture cut-off only deprives the engine of fuel, while not rapidly changing the dynamic loads on the piston/rod/crank interface during the simulated failure (remember the engine is still breathing air during a mixture cut). Rapid throttle movements (even during normal flight ops) is alleged to promote detuning of these critical crank balancing components, leading to their failure. Back in my prior life, I did a lot of C&T with counterweighted engines and never had a failure or complaint from the engineers at overhaul time. Maybe somebody else with time in these machines could share some knowledge/experiences.--CY

[Wee Weasley Welshman]

Mmmm. I see. You live and learn.

WWW

[The Scarlet Pimpernel]

Intersting topic this...I noticed in the opening gambit to the topic that CFS were mentioned. For what it's worth, in my experience both as a stude on several piston/jet aircraft and as an instructor on Tucanos I can quite honestly say that in a single engined aircraft I have never shut an engine down for demonstration purposes or had one shut down on me. (I cannot begin to imagine the subsequent board of enquiry if anything went pear shaped).
The only occasions where engine shutdowns are carried out (in my world anyway - 2 engined FJ) are on convex...one trip only to give you confidence in the ac flying on 1 donk (med/hi level to allow for several relights should the first not succeed) and on engine airtests.
Shutting down your only serviceable engine in flight is, I would say, pretty poor airmanship and could result in egg on your face.

[Meeb]

I am surprised that many experienced and intelligent people contributing to this forum are missing the point that the CAA REQUIRE an airstart as part of the (now defunct) 509 syllabus! If you want to make an issue of it, have a go at them, do not cast aspertions on the people who have been following syllabus directions.

Also, the point of the exercise is to practise engine re-starts, it has nothing to do with PFL teaching. The exercise has a hard deck of 5000' for re-start.

Soap box retracted...

[This message has been edited by Meeb (edited 22 September 1999).]

[Wee Weasley Welshman]

Airstart as part of 509? Never knew that. In which case things are a wee bit silly. A 509'er is supposed to be being prepared to go straight into airline ops where, forgive my ignorance, air starts are not likely to be required in 20 lifetimes of flying. Whereas being trained to be a FI is leading you to a situation where an air start during just one lifetime career is possible to likely.

Seems an anomaly to me.


WWW

[Tinstaafl]

Lycoming in their 'Lycoming Flyer' recommend using the mixture to simulate a failure. I can't recall if was for m/e only, or included singles.

Their reasoning is along the lines of what Corporate Yank said: The throttle butterfly remains open so there is still mass airflow into the cylinders. This provides a cushioning effect on the piston and associated connections - as would normally be experienced by those engine parts.

Something else it might affect is carby icing probability with a closed throttle but fuel from the idle jet still evaporating, compared to no fuel being evaporated at all? Haven't a clue on this, really, but it seems to make sense. Unless the greater mass airflow with an open throttle has a greater temp. drop of course.

As for the general thread of the topic, I think a properly structured shutdown exercise is beneficial. There are many things we do while teaching that have some level of 'risk' compared to straight & level. I don't believe that a shutdown poses any greater hazard than some of those.

Similarly, I can't see that a shut-down in a fixed-wing is more hazardous than motor-glider or sailplane as long as the aircraft is operated within it's glide performance envelope.

Of course you don't expect the same L/D & therefore glide range, but what does it matter if you're operating within an appropriate albeit different performance envelope? As I recall, gliders could range from (very approx)18:1 up to a modern high performance sailplane's 50 or 60:1. This is a far greater performance change factor than that experienced between a C150/152/172 / PA28 etc.

As with gliding, once the engine is shutdown then treat the flight as commited to land. Judicious choice of an appropriate environment is needed just as it is for any exercise.

[piston broke]

[climbs like a dog]

Surely the 509 requirement for an engine re-start would be met during the m/e part of the syllabus.

I also think that there is an acceptance issue here. If the shutting down of an engine on a single were to become an accepted exercise - on an FI course only or all licences, it would occur more often, and maybe not under ideal, supervised conditions. There's always some nugget who'll push it just too far and end up a statistic.

When shutting down and engine the Seneca checklist requires that cowl flaps are set to closed on the shut down engine in order to slow down engine cooling. I'm no engineer but on some of the simpler (non-cowl-flapped) s/e types aren't we running into the area of shock cooling, a bad habit we normally try to knock out of our students. Hmmmmm, maltreating the donkey too.

I also still think, in UK certainly, that no matter how ideal the situation, you can't account for the unplannable; such as ATZ-busting, conflicting traffic and you've got no options. He may have right of way but he doesn't know you're a glider (not that he'd probably care anyway).

The whole exercise should be the subject of a (thorough) ground briefing and then practiced possibly in a procedures trainer and/or touch drill in the air. Save the actual restart for if it's actually required.

The spin requirement was removed from the UK PPL syllabus because it was causing more accidents than it prevented. If in-flight re-starts were to become an accepted exercise I think there would be a similar correlation.

------------------
Get there eventually




[This message has been edited by climbs like a dog (edited 23 September 1999).]

[hugh flung_dung]

The current Lycoming guidance for twins is to use mixture above 3000 agl and throttle below 3000 agl. This seems to work OK, the justification is simple: using mixture is less stressful for the engine but below 3000 agl the stress level on the pilot could be raised to an unacceptable level :-)
For singles the only time I deliberately shut down the engine is as a required part of an aerobatic course. It's done using mixture, above 3000 agl, VMC, within range of good fields.

[Capt Homesick]

...and that's coz' I'm a wrinkly old PPRuNer who plans to get a lot older and wrinklier!

[Conscious Pilot]

In Oz in the old days (DCA etc) engine restarts in singles was part of the syllabus.

Two types were required - a normal shut down & start using the check lists - with some no engine handling & trimming for the glide.

Then you had to do a 'dive' restart. They were a lot of fun, and were always done over a good field, just in case.

I must have done hundreds of them with no hassells.

------------------
'of the varieties of the real & unreal, there are many!'